ARP High Performance series head bolt kits are tough! They are rated at 170,000 psi–15 percent stronger than Grade 8 fasteners. They come available with hex heads or reduced wrenching 12-point heads that eliminate the need for valvetrain removal when re-torquing cylinder heads.
23° Cast iron OEM, Gen III Vortec/Truck, most Edelbrock, LT-AFR, Brodix-8,-10,-11,-11xb,
LT-1, Dart Pro-1, Trick Flow heads & most World Products heads.